Heading south from Cape Cod toward NC today, Lucy by my side. Yes, it has been a long time since sailing much. Yes, I'm nervous about the currents and thunderstorms I'll be facing until around midnight. AND the temperature is supposed to plummet tonight, reaching around 50degF, so THAT will be darned chilly...
But then the temperatures should rise and winds should cooperate to bring me into Beaufort, NC or Cape Lookout around Monday. I may even have a day to spend walking with Lucy on the beaches before we need to head upstream to New Bern to store the boat and head to MI for a week, then CA for a month, before returning to chilly weather in mid-November and heading south to FL and/or the Bahamas.
What to write about... hmmm... How about a bit on batteries!
For years I've lusted after lithium (well, lithium iron phosphate) batteries, but always found the cost too high. But spring of 2020 found me sitting down to actually analyze the numbers and deciding when to swap over.... and I found the numbers added up then and there.... but only if I built my own system. So I ordered the cells and management electronics and had them delivered to a friend in Chatham, 
then picked them up and installed them.
What fun!
What is good about them compared to the good old lead acid batteries?
1) non toxic: one could grind them up and use them to fertilize a garden.
2) one can use over 80% of the battery capacity without damage compared to only about 50% with lead-acid.
3) They prefer to be left partially charged rather than requiring excess charge frequently, so I can keep more of the power my solar panels produce.
4) The new battery pack fits far more power and energy into the same footprint as my old batteries.
5) I can take part of my battery bank, put it in the dinghy, and putter around with a trolling motor.
6) Power tools now run far better as the batteries can put out far more power than lead acid.
Problems?
1) Existing charging electronics on my boat are not quite right and may occasionally create a problem. I have a work-around, but it takes attention if I am running my engine much.
2) The LiFePO4 batteries don't like freezing weather and charging them when they are below freezing will destroy them rapidly.
3) I can now find some cells for under half of what I paid. All electric cruising, anyone? No more propane, diesel, or oil on board! I'd love it.... maybe in a year or five.
